Apple this week seeded a golden master of Xcode 4 to developers with documentation that mistakenly referenced Mac OS X 10.7 Lion, only to pull the software and re-seed it without any mention of the forthcoming Mac operating system update.

People familiar with the Xcode 4 golden master available to developers say the release requires an Intel-based Mac running Mac OS X 10.6.6 or later. Previously, the software was temporarily available with documentation that said mistakenly Xcode 4 would actually require Mac OS X 10.7 Lion. No seeds of Lion have been made available to developers.

The Xcode 4 package includes software development kits for Mac OS X 10.6 Snow Leopard, and iOS 4.2. It is also compatible with Xcode 3.2.x project files.

The golden master released to developers this week reportedly resolves an issue when editing .nib files that existed in the previous release, known as Preview 6. New snapshots are also said to properly appear in the projects organizer when a project has no snapshots.

Apple's Xcode 4 has a brand new, single-window interface for all major workflows, and the Interface Builder is integrated with the main Xcode IDE. Other major features include fix-it, which highlights code in real-time where an error is detected and can address the problem, and a faster LLDB debugger that uses less memory than the GDB debugging engine.

Xcode allows developers to create applications for the Mac, iPhone and iPad. Using the Xcode 4 golden master seed, developers can now submit iOS and Mac apps to the App Store.